Major efforts included: 1) collaboration with the Committee on Biological Effects of Ionizing Radiation of the National Academy of Sciences to evaluate available data on risk to alpha-emitting radionuclides 2) analysis of the interactive effects of joint carcinogen exposures in large rodent studies, 3) the planning and implementation of cohort and case-control studies in China to quantify the joint effects of smoking and exposure to arsenic and radon on lung cancer risk and to investigate risk factors for penile cancer, 4) studies on the effects of ultraviolet radiation on skin cancer, 5) evaluation of case-control data on dietary risk factors for esophageal cancer, 6) collaboration and consultation on the design and analysis of cohort studies in groups at risk of acquired immunodeficiency syndrome (AIDS), 7) joint evaluation of serum markers for lung cancer, 8) consultation with the Division of Cancer Prevention and Control, NCI, on large-scale prevention and intervention trials, 9) evaluation of cancer risk from occupational exposures in Montreal, 10) evaluation of leukemia risk following treatment of ovarian cancer, 11) evaluation of thyroid cancer risk in persons exposed to head and neck radiation in childhood, and 12) evaluation of the risk of early menopause in a cohort of survivors of childhood cancer.